Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenue	$ 1,134,468	$ 650,067	$ 399,020
Cost of revenue	525,551	300,841	182,895
Gross profit	608,917	349,226	216,125
Operating expenses:
Research and development	391,355	171,358	120,739
Sales and marketing	369,079	175,555	100,669
General and administrative	218,268	117,548	60,791
Total operating expenses	978,702	464,461	282,199
Loss from operations	(369,785)	(115,235)	(66,074)
Other income (expense), net	7,569	(5,923)	3,071
Loss before provision for income taxes	(362,216)	(121,158)	(63,003)
Income tax benefit (provision)	55,153	(791)	(705)
Net loss attributable to common stockholders	$ (307,063)	$ (121,949)	$ (63,708)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (2.36)	$ (1.26)	$ (0.70)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted (in shares)	130,083,046	97,130,339	91,224,607